Piezoelectric generating device

ABSTRACT

A piezoelectric generating device in which a hammer is supported within an outer case through a pair of hammer cams rotatably arranged on the hammer. The hammer will thus impart a blow against a piezoelectric element unit by the operation of a manipulator.

United States Patent Mariya Sept. 2, 1975 [54] PIEZOELECTRIC GENERATING DEVICE [56] References Cited [75] Inventor: Nobuyoshi Moriya, Urawa, Japan NITED STATES PATENTS [73] Assignee: Mansei Kogyo Kabushiki Kaisha, g E Japan 3,793,561 2 1974 Lundh 310/87 x [22] Filed: Feb. 20, 1974 Primarv Examiner-Mark O. Budd 3 [7]] Appl' 444132 Allorney, Agent, or Firm-Armstrong, Nikaido &

Wegner [30] Foreign Application Priority Data Mar. 2, 1973 Japan 4324072 11 [57] ABSTRACT 1973 Japan 48'26928w] A piezoelectric generating device in which a hammer is supported within an outer case through a pair of 52 us. (:1 310/s.7; 317/1310. 11 hammer Cams rotatably arranged on the hammer. The [5 t t hammer h i p a blow against a piezoelectric [58] Field of Search 310/83, 847, 9.1; 317/81, element unit by the Operation of a manipulator 317/96, DIG. ll; 43l/l43, 255

18 Claims, 7 Drawing Figures PIEZOELECTRIC GENERATING DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is related to a piezoelectric generating device of ignition apparatus, and more particularly to an improved piezoelectric generating device which is used for gas stoves, gas cookers, cigarette gas lighters or the like.

2. Brief Description of the Prior Art I-Ieretofore various piezoelectric generating devices have been disclosed. For example, US. Pat. No. 3,509,388 shows a high voltage generating device including a piezoelectric element, a hammer for striking the piezoelectric element, an accumulating spring for storing the energy required to drive the hammer toward the piezoelectric element and a manipulator for controlling the hammer. According to the teachings of the US. Patent, the accumulating spring is interposed with torsion between the manipulator and the hammer, and one end of the spring is fixedly secured on the top end of the hammer to rotate the hammer so that the hammer rests spaced from the piezoelectric element. Therefore this structure requires much skill in assembling the device and in replacing its parts with new ones when some parts of the device are damaged. Further, the interposed accumulating springs shall be stressed and simultaneously twisted so as to drive the hammer toward the piezoelectric element. Accordingly the accumulating spring and its parts operatively connected therewith are susceptible to be damaged due to repeatedly continuous operations of the generating device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved piezoelectric generating device which is easily assembled or repaired.

Another object of the present invention is to provide an improved piezoelectric generating device which is durable against continuous operations.

These and other objects and advantages of the invention may be easily ascertained by referring to the following description and appended drawings in which:

FIG. 1 is an elevational view of the inoperative position of the piezoelectric generating device according to the present invention;

FIG. 2 is an elevational view in section showing the inoperative position of the piezoelectric generating device shown in FIG. 1;

FIG. 3 is an elevational view in section showing the operative position of the piezoelectric generating device shown in FIGS. 1 and 2;

FIG. 4 is an enlarged perspective view showing a hammer and a pair of hammer cams of the piezoelectric generating device shown in FIGS. 1 to 3;

FIGS. 5, 6 and 7 show another embodiment of a piezoelectric generating device according to the present invention, FIG. 5 being an elevational view, FIG. 6 being an elevational view in section and FIG. 7 being an enlarged perspective view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 to 4, an outer case 1 has a conventional piezoelectric element unit 2 fixedly secured on the bottom thereof and a manipulator 3 is slidably held within the outer case 1 by a pair of hammer cams 4 under the upward influence of a return spring 5 arranged between the manipulator 3 and the piezoelectric element unit 2.

A hammer 6 is maintained spaced from the piezoelectric element unit 2 by the pair of hammer cams 4 which are rotatably arranged in a transverse opening 8 of the hammer 6. This transverse opening 8 is formed beside the central axis of the hammer 6 to provide space for the cams 4.

Each hammer cam 4 has a first arm 4a which is in operative connection with the manipulator 3 and a second arm 4b which acts to limit the movement of the hammer cam 4 in such a manner hereinafter described. The first arm 4a is designed to extend horizontally in its inoperative position of the hammer cam 4 to engage a projection 9 of an opening 10 formed on the side wall of the manipulator 3. This projection 9 acts as restoring means for the hammer cam 4 to lift the hammer cam 4 to its initial upward position. The second arm 41) has a cutout portion 4b which is designed to engage a retaining portion 11 of a guiding slot 12 formed on the outer case 1 so as to limit the upward and rotational movements of the hammer cam 4.

The guiding slot 12 which acts as guiding means for the hammer cam 4 has a horizontal portion 12a which is wider than the first arm 4a of the hammer cam 4 for the purposes hereinafter described. The guiding slot 12 has further a guiding portion 12b which extends longitudinally to direct the upward and downward movements of the hammer cam 4. The above-mentioned retaining portion 11 is formed in the guiding portion 12b, and below the retaining portion 11 there is formed a sliding seat 11a which is adapted to maintain the second arm 4b of the hammer cam 4 while an energy accumulating spring 7 stores a predetermined striking energy therein upon depression of the manipulator 3. A sufficient space is provided between the retaining portion 11 and the sliding seat 11a for the rotation of the second arm 4b of the hammer cam 4.

The horizontal portion 12 is formed to facilitate the arrangement or replacement of the hammer cam 4 in the transverse opening 8 of the hammer 6. After the hammer 6 is installed with the energy accumulating spring 7 within the manipulator 3, the hammer cam 4 is placed through the guiding slot I2 formed on the outer case 1 and the opening 10 formed on the manipulator 3 by slightly raising the hammer 6 with a tool or the like. For the purposes, a through bore 40 is provided on one of the hammer cams 4. When the hammer cams 4 are required to be replaced due to damage, for instance, they may be easily taken out of the hammer 6 by pushing the opposite hammer cam 4 with a fine pin or the like, after the coincidental adjustment is made to register the positional relation between the hammer and the horizontal portion of the guiding slot 12. In the normal position of the hammer 6, the first arm 40 of each hammer cam 4 is positioned within the outer case 1 and kept in its position by the side wall of the outer case 1.

Upon depressing the manipulator 3 against the action of the energy accumulating spring 7, the striking energy is st aed in the accumulating spring 7 while the second arm 4b of the hammer cam 4 comes into contact with the sliding seat 11a formed in the guiding slot 12 to maintain the hammer 6 in spaced relationship with the piezoelectric element unit 2. When the predetermined striking energy is stored in the accumulating spring 7, the upper horizontal end 10a of the opening 10 is brought into engagement with the first arm 4a of the hammer pin 4 to rotate the hammer cam 4 in the counterclockwise direction in the transverse opening 8 of the hammer 6. This counterclockwise rotation of the hammer cam 4 causes the second arm 4b to disengage from the sliding seat 11a and the hammer 6 is rapidly driven under the action of the accumulating spring 7 to impact a blow against the piezoelectric element unit 2.

The hammer 6 returns to its initial position by the action of the return spring together with the manipulator 3 through the hammer cam 4 arranged on the hammer 6. In the upward movement of the manipulator 3, the projection 9 of the opening 10 comes into contact with the end portion of the first arm 4a of the hammer cam 4 and lifts the hammer cam 4 with the hammer 6, while the second arm 4b is also raised along the guiding portion 12b of the guiding slot 12 until the cutout portion 4b engages the retaining portion 1 1 of the guiding slot 12. This engagement of the second arm 4b with the retaining portion 11 is effected by the rotation of the hammer cam 4 toward the sliding seat 11a in the guiding slot 12 and the manipulator 3 is held by this engagement in its inoperative position.

The second embodiment, illustrated in FIGS. 5, 6 and 7, comprises an outer case 101 which is provided with a pair of longitudinal guiding slots 102 in the upper section thereof. The pair of guiding slots 102 are diametrically opposed and each slot 102 has a retaining portion 103 and a sliding seat 103a which is formed below the retaining portion 103. A manipulator 104 is arranged in telescopic relationship with the outer case 101 and formed with rectangular openings 104a. The rectangular openings are also diametrically opposed and are provided with a horizontal end 104b and a replacement end 1046 to operate a pair of hammer cams 105 with first andsecond arms 105a and 1051; by which a hammer 6 is kept in spaced relationship with a piezoelectric element unit 2 fixedly secured on the bottom of the outer case 101. Between the pair of hammer cams 105 there is provided a restoring spring 106 which is adapted to rotate the hammer cams 105 to their initial inoperative position. Both ends of the restoring spring 106 are engaged in respective notches 1056 of the hammer cams 105 arranged in a transverse opening 8 of the hammer 6.

An energy accumulating spring 7 is interposed between the manipulator 104 and the head portion of the hammer 6, and a return spring 5 is between the lower end of the manipulator 104 and the shoulder portion of the piezoelectric element unit 2 which is provided with a lead wire 2a.

Upon depressing the manipulator 104, the second arm 105b of the hammer cam 105 engages the sliding seat 103a of the longitudinal guiding slot 102 and the energy accumulating spring 7 stores energy which drives the hammer 6 toward the piezoelectric element unit 2 to impart a blow against the latter. When the upper horizontal end 104b of the rectangular opening 104a comes into contact with the first arm 1050 of the rotatable hammer cam 105, the hammer cam 105 rotates in the counterclockwise direction to disengage from the sliding seat 103a and the hammer 6 is rapidly propelled by the energy stored in the accumulating spring 7.

The hammer 6 is returned by the action of the return spring 5 and is maintained in its initial position by the hammer cam arranged on the hammer 6. At first, the manipulator 104 is moved upward by the action of the return spring 5, and then in the upward movement of the manipulator 7 of the replacement end 1046' of the rectangular opening 104a engages the lower end of the second arm 105b to raise the hammer 6 along the guiding slot 102. On the predetermined path of the upward movement, the hammer cam 105 is rotated toward the retaining portion 103 of the guiding slot 102 by the restoring spring 106 to engage the retaining portion 103. In this way, the manipulator 104 and the hammer 6 take their intial positions and both are held by the hammer cam 105 for further action.

While there has been described preferred embodiments of the invention, obviously modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

I claim:

1. A piezoelectric generating device comprising:

a case;

a piezoelectric element unit;

a hammer;

a hammer cam mounted on said hammer and being rotatable between first and second positions to control said hammer;

said hammer cam including first and second arms thereon; an energy accumulating spring for storing energy to drive said hammer toward said piezoelectric element unit;

a manipulator means moveable in relation with said case to stress said energy accumulating spring and to rotate said hammer cam between its first and second position;

guide means formed on said case and adapted to direct the movement of said hammer cam;

said guide means including a retaining means for engaging said second arm of said hammer cam to limit the rotational movement of said hammer cam;

said guide means further including a sliding seat means for engaging said second arm of said hammer cam to maintain said hammer spaced from said piezoelectric element unit while said manipulator moves to store the energy in said energy accumulating spring, wherein when said manipulator rotates said hammer cam to its second position, said second arm is disengaged from said sliding seat whereby said hammer is rapidly driven toward said piezoelectric element unit by the energy stored in said spring.

2. A piezoelectric generating device according to claim 1, wherein said sliding seat is formed between said retaining portion of said guide means and said piezoelectric element unit.

3. A piezoelectric generating device according to claim 2, wherein said sliding seat has a surface slanting toward said piezoelectric element unit.

4. A piezoelectric generating device according to claim 3, wherein said guide means includes a longitudinal slot formed in said case extending toward said piezoelectric element unit, wherein said retaining portion and said sliding seat control the movement said hammer cam.

5. A piezoelectric generating device according to claim 4, wherein space is provided between said retaining portion and said sliding seat for the rotational movement of said second arm of said hammer cam.

6. A piezoelectric generating device according to claim 5, wherein said second arm of said hammer cam includes an extension on one side thereof, said extension adapted to engage said retaining portion said guideing means.

7. A piezoelectric generating device according to claim 6, wherein said guide means has a horizontal slot extending laterally from said longitudinal slot for mounting said hammer cam on said hammer.

8. A piezoelectric generating device according to claim 7, wherein said horizontal slot is formed on the same side as said retaining portion of said guide means.

9. A piezoelectric generating device according to claim 6, wherein said hammer includes a transverse opening formed therethrough said transverse opening adapted to accomodate a hammer cam on each end thereof, and wherein said guide means is formed on opposite sides of said case.

10. A piezoelectric generating device according to claim 9, wherein said restoring means is arranged between said hammer cams to bring said second arms into engagement with said retaining portions of said guide means.

11. A piezoelectric generating device according to claim 10, wherein said restoring means is a coiled spring the opposed ends of which are respectively engaged with the inner sides of said hammer cams within said transverse opening.

12. A piezoelectric generating device according to claim 9, wherein a through bore is formed on one of said hammer earns.

13. A piezoelectric generating device according to claim 9, wherein said manipulator includes a pair of rectangular openings on the opposite side walls thereof. said rectangular openings each having an upper end adapted to engage said first arm of said hammer cams.

14. A piezoelectric generating device according to claim 13, wherein said pair of rectangular openings have respectively a projection inwardly extending to engage said first arm of said hammer cams to lift said hammer.

15. A piezoelectric generating device according to claim 13, wherein said rectangular opening has a lower end adapted to engage the lower end portion of said second arm of said hammer cam to lift said hammer when said hammer cam returns from the second position to the first position.

16. A piezoelectric generating device according to claim 10, wherein said transverse opening is formed on the central axis of said hammer.

17. a piezoelectric generating device according to claim 10, wherein said transverse opening is formed beside the central axis of said hammer.

18. A piezoelectric generating device according to claim 1 1, wherein each inner end of said hammer cams has a notch therein which engages the end of said coiled spring. 

1. A piezoelectric generating device comprising: a case; a piezoelectric element unit; a hammer; a hammer cam mounted on said hammer and being rotatable between first and second positions to control said hammer; said hammer cam including first and second arms thereon; an energy accumulating spring for storing energy to drive said hammer toward said piezoelectric element unit; a manipulator means moveable in relation with said case to stress said energy accumulating spring and to rotate said hammer cam between its first and second position; guide means formed on said case and adapted to direct the movement of said hammer cam; said guide means including a retaining means for engaging said second arm of said hammer cam to limit the rotational movement of said hammer cam; said guide means further including a sliding seat means for engaging said second arm of said hammer cam to maintain said hammer spaced from said piezoelectric element unit while said manipulator moves to store the energy in said energy accumulating spring, wherein when said manipulator rotates said hammer cam to its second position, said second arm is disengaged from said sliding seat whereby said hammer is rapidly driven toward said piezoelectric element unit by the energy stored in said spring.
 2. A piezoelectric generating device according to claim 1, wherein said sliding seat is formed between said retaining portion of said guide means and said piezoelectric element unit.
 3. A piezoelectric generating device according to claim 2, wherein said sliding seat has a surface slanting toward said piezoelectric element unit.
 4. A piezoelectric generating device according to claim 3, wherein said guide means includes a longitudinal slot formed in said case extending toward said piezoelectric element unit, wherein said retaining portion and said sliding seat control the movement said hammer cam.
 5. A piezoelectric generating device according to claim 4, wherein space is provided between said retaining portion and said sliding seat for the rotational movement of said second arm of said hammer cam.
 6. A piezoelectric generating device according to claim 5, wherein said second arm of said hammer cam includes an extension on one side thereof, said extension adapted to engage said retaining portion said guideing means.
 7. A piezoelectric generating device according to claim 6, wherein said guide means has a horizontal slot extending laterally from said longitudinal slot for mounting said hammer cam on said hammer.
 8. A piezoelectric generating device according to claim 7, wherein said horizontal slot is formed on the same side as said retaining portion of said guide means.
 9. A piezoelectric generating device according to claim 6, wherein said hammer includes a transverse opening formed therethrough said transverse opening adapted to accomodate a hammer cam on each end thereof, and wherein said guide means is formed on opposite sides of said case.
 10. A piezoelectric generating device according to claim 9, wherein said restoring means is arranged between said hammer cams to bring said second arms into engagement with said retaining portions of said guide means.
 11. A piezoelectric generating device according to claim 10, wherein said restoring means is a coiled spring the opposed ends of which are respectively engaged with the inner sides of said hammer cams within said transverse opening.
 12. A piezoelectric generating device according to claim 9, wherein a through bore is formed on one of said hammer cams.
 13. A piezoelectric generating device according to claim 9, wherein said manipulator includes a pair of rectangular openings on the opposite side walls thereof, said rectangular openings each having an upper end adapted to engage said first arm of said hammer cams.
 14. A piezoelectric generating device according to claim 13, wherein said pair of rectangular opEnings have respectively a projection inwardly extending to engage said first arm of said hammer cams to lift said hammer.
 15. A piezoelectric generating device according to claim 13, wherein said rectangular opening has a lower end adapted to engage the lower end portion of said second arm of said hammer cam to lift said hammer when said hammer cam returns from the second position to the first position.
 16. A piezoelectric generating device according to claim 10, wherein said transverse opening is formed on the central axis of said hammer.
 17. a piezoelectric generating device according to claim 10, wherein said transverse opening is formed beside the central axis of said hammer.
 18. A piezoelectric generating device according to claim 11, wherein each inner end of said hammer cams has a notch therein which engages the end of said coiled spring. 